Electrophotographic toner cartridges of the unitary type may include a developer section and a photoconductor or cleaner section connected to one another so that the developer roller, of the developer, may be pressed against the photoconductor drum, of the photoconductor, with a predetermined and controlled pressure. The controlled pressure may often be provided by permanently installed springs stretching between the two units such that the two units are not separable, thereby forming a unitary or one piece replaceable cartridge.
Such one piece toner cartridges may have the advantage of having the springs installed at the factory manufacturing the cartridge. Since the springs may have a relatively short operational life, the entire cartridge may be factory refurbished (or discarded) upon depletion of the toner supply whereupon new springs may be installed.
Two piece cartridges are also known in which the developer housing, of the toner, may be separated from the photoconductor or cleaner housing. When such two piece cartridges are installed in a typical printing device, they may be manually brought together, by the user, and interconnected by a latching mechanism, such as a resilient latch, lever, or springs of some sort, whereby the two units may be drawn together with the required pressure between the developer roll and the photoconductor roll for satisfactory imaging. The removable cartridge may include a photoconductive (PC) drum rotatably supported in the cleaner housing and a developer roller rotatably supported in the developer housing, which is slidably received in the cleaner housing. The developer roll may transfer toner from the developer housing to the photoconductive drum when both are rotating to print a latent image on a recording medium.